What is a Pitman arm on an offroad truck?

Pitman arms are used on vehicles with conventional suspension systems and parallelogram steering. Almost all rear-wheel-drive vehicles and most trucks are equipped with this type of suspension and steering arrangement. With a threaded bearing stud and seat, the Pitman arm is connected to the steering gear by a splined arm. It is necessary to protect the bearing and seat from dirt by covering the lower part of the threaded bearing stud with a dust boot. Bearing studs are attached to steering linkage center links at their upper ends.

During steering, the Pitman arm is attached to the steering gear shaft and acts as a lever converting torque from the steering gear into mechanical force.

Suggestions and Tips for Maintenance

Besides lubricating the Pitman arm during every oil change, other suspension components should also be inspected annually, along with an alignment of the wheels. A worn Pitman arm can result in loose or erratic steering, wandering, tire edge wear, and play on the steering wheel. A qualified service professional can inspect your idler arm; techniques and specifications vary.

The Role of The Pitman Arm in Offroad Trucks

Pitman arms are an integral part of any steering system that makes use of a steering box since they are the parts that attach to the steering box output shaft. Here are some details about Pitman arms and their use in different models.

Some 4-wheel drive trucks have a different steering box output shaft and Pitman arm arrangement than 2-wheel drives. Pitman arms point to the side of the truck, while draglinks run toward the back of the truck to the steering knuckle. Pitman arms on 2WDs point straight back, and the centerlinks move side to side to steer the tires by moving the tierods. 

Besides internal tuning differences, the steering boxes of 2wd and 4wd are identical except for the output shafts. The important detail is that a 2wd box will bolt up directly into a 4wd box since the bolt pattern is the same on the housing. When you turn the wheel, the steering box also moves the output shaft in the same direction. However, in use, the Pitman arms start pointing in different directions, making the steering boxes appear different.

Using a 2wd box and a Pitman arm with the appropriate spline, length, drop and end taper will allow us to convert a solid axle truck to crossover steering.

If we used a Pitman arm, we wouldn’t have to swap steering boxes if we used the stock 4WD output shaft. Since the cross-bolt had to stay in the same position relative to the output shaft, the Pitman arm configuration would get a little weird. If we did this, the cross-bolt would likely have to be threaded into the Pitman arm instead of a nut, or stud and nut would have to be used. Either way, it’s awkward.  That’s the small problem. The bigger problem is the weak and wear-prone factory 4WD output shaft that’s only splined for a short section.  

The 2wd Pitman arm uses a taper fit on a splined shaft and is held tight on the taper with a single nut. This has proven by far to be a MUCH more reliable system when under tougher use than the 4wd Pitman arm.

Another question is why not use the 2WD Pitman arm? When you look at the 2WD Pitman arm, you will see that it is not suitable for crossover steering use.

It is important to know that the GM output shafts from 1967 to 1998 have four master splines, which allow the Pitman arm to slide into one of four specific rotational positions. Starting in ’99, some trucks had three index splines and some had four index splines. Some Pitman arms do not have corresponding index splines and can be mounted in any orientation. This allows you to use the same Pitman arm on Ford, Dodge, GM, Chevy, and Jeep steering boxes.  During installation, you have to make sure the arm points straight back, but that isn’t very challenging.

If you want to get deep into Pitman arm knowledge, here’s a tidbit you might not know: Pitman arms are often welded on custom builds when you need a drop, length, or taper that is unavailable. Pitman arms are generally made of forged steel. This is only used on very custom builds when a specific length, drop, or taper is needed. Welding on steering components like this is an expert-level job, so we won’t go into it in detail, but it is cool to know you can do it.

Does a Pitman arm last for a long time?

To ensure that you can steer safely while driving, your vehicle’s steering system is quite complicated and requires a lot of components to work together. Pitman arms connect the steering gear to the steering linkage, which leads to the wheels, which is one of the most critical components.

Every time you turn the steering wheel, the Pitman arm is used. Despite this, the Pitman arm is incredibly durable, and with the proper maintenance and service schedule, it can last for a very long time. It can, however, be damaged in several ways, including auto accidents, when it is left loose after being serviced, and when it is neglected.

Pitman arms are prone to wear and tear to their ball sockets, which are located at the end of the arms. This ball joint will eventually wear out and require replacement. However, regular lubrication can extend its life. To prevent these problems from becoming severe, Pitman arms and other front-end components should be lubricated at every service (oil change).

The Pitman arm plays an important role in controlling the vehicle, so you must know what signs and symptoms to watch for. These include:

  • In the area of the Pitman arm, there is grease around the boot (this may indicate damage to the idler arm or tie rod end, or to the Pitman arm itself)
  • It feels like your steering is slipping, or it feels abnormal
  • The steering wheel has too much play
  • There is a feeling that the steering is wandering

The sooner you detect any of these symptoms, the better. A certified mechanic can inspect your vehicle and replace your Pitman arms, as well as any other front-end components so that you can return to driving safely.

What is the importance of a Pitman arm?

Using a ball joint, the Pitman arm moves in a circular motion while connected to the sector shaft of your vehicle. It is part of the steering system. When you turn the steering wheel in any direction, the wheels move left or right. To keep your Pitman arm in good working condition, you should watch for the following symptoms of a bad or failing Pitman arm. Poor steering can be hazardous to you and those around you.

Poor steering performance

If you notice your steering wheel turns more than it should before your wheels engage, your Pitman arm probably needs to be checked. Since it is part of your steering system and is critical for the proper operation of the steering system, Your mechanic should handle the diagnosis and repair of this component. Get your Pitman arm replaced as soon as you notice your vehicle isn’t steering as well as it used to.

Wandering to the left or right while driving

Having trouble steering your vehicle or pulling to one side? Your Pitman arm is probably malfunctioning or failing. If you turn the wheel, your vehicle may not respond properly. As well as having a lot of play, it can also be highly inaccurate or act as if it has a mind of its own while you are driving. This can be particularly dangerous in hazardous conditions or on a busy highway.

Unable to steer

When the Pitman arm completely fails, all steering in your vehicle will stop working. The Pitman arm needs to be replaced before it gets to this point. This is a dangerous situation, so if you notice any of the symptoms above, you should get it checked before it completely fails. If you lose steering, don’t drive. Stop as safely as possible and call for help.

Pitman arms need to be replaced if your steering is poor, your vehicle wanders, or you have lost all steering control. It is best to book a service with your mechanic as soon as possible before your steering completely fails. 

Pro-tip: For safety, inspect your Pitman arm for wear and replace it as needed when you drive off-road a lot.

What is the difference between an idler arm and a Pitman arm?

What is an idler arm?

Typically, the idler arm assembly is made up of a rod that pivots on a bracket bolted to the vehicle’s frame, and a ball socket on the other end of the rod. As a general rule, an idler arm holds the center link at the proper height so that the Pitman arm’s movement can be accurately relayed to the vehicle’s frame on the opposite side of the center link from the Pitman arm. Because of the pivot function built into idler arms, they are generally more prone to wear than Pitman arms.

How long do idler arms last and why do they fail?

You can extend the life of your idler arm with proper maintenance and care. The idler arms can wear more quickly, however, depending on how you drive, the road conditions, and lack of lubrication and maintenance. Idler arms can also become damaged in an accident or leave themselves loose after service, resulting in the need to replace them.

Do idler arms cost a lot to Replace?

As well as the amount of labor involved, replacing idler arms varies from vehicle to vehicle. If you are replacing a steering component, you may need to replace both the idler arm and the Pitman arm. While replacement parts are generally not very expensive, steering components often take some time to assemble and test. You will usually need an alignment when adjusting or replacing idler arms.

What happens if a Pitman arm fails?

If your idler arm or pitman arm fails, your vehicle may not respond appropriately when you turn the steering wheel. As a result, you may notice your vehicle pulling to one side or having difficulty steering.

How do you tell if a Pitman arm is bad?

A bad Pitman arm will cause loose or unresponsive steering. A damaged tapered hole or worn ball joint will cause enough play in the steering to make it feel vague when turning the wheel.

What causes a Pitman arm to break?

Pitman arms that are weak are pretty much guaranteed to break at low speeds during turning in a parking lot because the force on the Pitman arm is much greater at low speeds.


Are Pitman arms susceptible to wear and tear?

Pitman arms that do not have any moving parts need to be replaced after impact damage (from collisions, etc.) or damage to their tapered holes.

That said, another type of Pitman arm connects to the steering linkage with a movable ball joint that can eventually wear out.

What is the best way to test my Pitman arm?

The easiest way to check a Pitman arm is to do a dry-park test. Simply have someone turn the steering wheel back and forth while the vehicle is on the ground. Watch the Pitman arm as it is turned and note any play.

Can you drive with a bad Pitman arm?

If the Pitman arm fails, you could lose steering ability completely. A faulty Pitman arm should be replaced as soon as possible.

What is the average time it takes to change a Pitman arm?

Replacement of a Pitman arm depends on many factors, including the type of vehicle you have and your skillset (if you decide to tackle the job yourself). A special puller is typically required to do this job, but if you’re handy, you can find kits here and here.